Their lives, like those of thousands of other Americans, were about to be changed forever on a day that will be etched indelibly in history.

In the hours that followed, the worst assault ever against America would unfold in a drama never before seen on the U.S. mainland. More than twice as many would die on Tuesday, Sept. 11, 2001, as did at Pearl Harbor on Dec. 7, 1941.

And the events would happen right before our eyes -- not through the distant telegraph messages and delayed radio broadcasts that reported the start of World War II.

Cindy Handler was watching television as a second jetliner slammed into the World Trade Center, right above the floors where her husband was working. People caught up in events, even aboard hijacked planes, communicated by cellphones. Others fleeing explosions picked up news with digital pagers and Palm-type handheld devices.

This was terror in the age of instant media, a day of horrific images made up of thousands of individual stories.

And for one long day, the news seemed to be getting worse with each hour.

8 a.m. Boston: Ninety-two persons were on board American Airlines Flight 11 as it took off from Logan International Airport, bound for Los Angeles.

One of them was Jeffrey Coombs, a 6-foot-3, 230-pound bear of a man who liked to hike.

A Compaq program manager, he was a frequent flier, but when his wife, Christie, had dropped him off at the train station for a four-day business trip, she felt guilty that their leave-taking had been so perfunctory.

They had been married for 17 years, had three children, but still, "for some odd reason," Christie recalled, "as he was walking to the train, it went through my mind very quickly that that was a casual kiss. What if this was it? I don't know why I thought it. It was just a quick, fleeting thought."

A fellow passenger was Paige Farley Hackel, 46, of Newton, Mass. On the board of directors of the local Salvation Army, she was traveling to Los Angeles for a self-improvement seminar, and had planned to go on to Denver to meet her husband, Allan Hackel, 73.

Hackel had been planning to fly with her best friend, Ruth Clifford McCourt of New London, Conn. But they couldn't get tickets together on the same plane. McCourt and her 4-year-old daughter, Juliana, were booked on United Flight 175, scheduled to leave about the same time.

Two groups of terrorists -- five on each flight -- had booked themselves on these two Boston planes. Two other groups -- one comprising of five men, the other of four -- were preparing to fly on planes leaving other airports in the next few minutes. All four flights were bound for the West Coast, meaning they were laden with fuel.

At 8:14 a.m., United Flight 175 left Boston for Los Angeles. On board were 65 people, including the McCourt mother and daughter.

At 8:21 a.m., American Flight 77 departed Washington's Dulles International Airport for Los Angeles with 64 on board, five of them terrorists. One passenger was Mari-Rae Sopper, a 35-year-old lawyer, champion gymnast and former Navy lieutenant. She had just quit her job in a Washington law firm to become the head women's gymnastics coach at the University of California, Santa Barbara.

Also aboard was Buddy Flagg, a retired Navy rear admiral, and his wife, Darlene, making a visit to their son in California.

Twenty-two minutes later, United Flight 93 took off from Newark, N.J., with 45 on board, including four terrorists.

Radar records show that the Newark and Dulles planes had tranquil starts, gradually climbing to their 35,000-feet cruising altitude, but the Boston planes were apparently seized by hijackers shortly after takeoff.

At 8:15 a.m., American Flight 11, a Boeing 767, suddenly veered north from its planned route. Fourteen minutes later, Flight 11 suddenly swung south toward New York City.

At 8:48 a.m., Debbi Gibbs, a manager in the record industry, was jogging near Stuyvesant High School, four blocks from the World Trade Center. She looked up to see an American Airlines plane. "Jesus, that's low," she thought. It flew directly over her head and smashed into the north tower, striking in the area of the 95th floor, cutting out a huge hole as if the building were plastic. Fire and smoke billowed out.

It was an astonishing display of physics. The Boeing 767-200, 156 feet wide, slammed into the tower at close to its cruising speed of 530 mph. That was crucial.

If it had been going half as fast, the impact would have been four times less, according to Barnes McCormick, an aerospace engineering professor at Penn State. The plane struck with the force of a 175-ton brick dropped from a height of 6,000 feet.

HELP FOR THE INJURED
Pregnant woman assisted in escape from the 77th floor

On the 77th floor, the paneled ceiling collapsed, the floor trembled and the sprinklers turned on, soaking Fred Segro, a manager at Martin Progressive, a technology consulting firm.

Nearby, a pregnant secretary named Julie was splattered with a large plate-glass window that pushed her backward, and she hit her head on the desk behind her.

As dense smoke filled the offices, Julie moaned, "My baby, my baby." She is about three months pregnant.

Segro had worked with her for only three weeks. He didn't even know her last name, but he offered to help her. He wrapped his tie and a paper towel around her cut wrist and put another paper towel on her cut head.

As they started down the stairs, Segro was amazed at how calm the people were. People stepped aside for the injured. Two men were carrying a woman down. Many were bleeding from their heads and arms.

"I remember this one guy, a black man, his skin was burned off -- he was totally pink on his arms, legs, the sides of his face."

On the ground level, Michael DeVito was just entering the north tower lobby. He was late for his job on the 77th floor, where he worked with Segro, because he had stayed up late watching a new TV show, Shipmates. He overslept and missed his train.

Now, as he walked into the lobby, he felt a huge explosion. A massive blast of air struck him. He guessed it was a suitcase bomb, but apparently it was air from the plane crash shooting down the elevator shafts.

Black smoke filled the lobby. DeVito stumbled outside. He looked up to see flames shooting from the building. People were jumping out of windows.

Across the plaza, on the 67th floor of the south tower, Harry Handler, systems director for the Morgan Stanley financial services firm, heard the roar of jet engines, then saw an explosion go right through the north tower. He watched showers of steel and glass cascading down.

Handler decided immediately to evacuate his people. He didn't dream of a second assault by plane, but he had heard about the 1993 terrorist bombing at the World Trade Center that filled the building with smoke.

For the next few minutes, he roamed throughout the floor, ordering his people to move quickly down the stairwells. Someone told him that a person with a bullhorn was standing on the 44th floor -- an elevator interchange area -- telling people the south tower was not in danger and to return to their offices.

A PLEA FOR DEPARTURE
Businessman stays to guide people from higher floors

Handler disagreed. Better get them out now. He took a moment to call his wife and tell her that the north tower had been hit, but that he was all right.

Even after all his people left, Handler stayed behind, because people had come down from other floors, stopping to look out the windows at the astonishing destruction next door. Handler urged them to get going.

At 8:51 a.m., while chaos spread through lower Manhattan, American Flight 77, having reached its cruising altitude at which the seat belt signs could be switched off, was over Ohio when it suddenly made a turn back to the east. Its transponder was switched off.

At 8:59 a.m., United Flight 175, which had been on course west, suddenly turned north over New Jersey and headed toward southern Manhattan.

At 9:03 a.m., Cindy Handler was watching TV in her Montclair, N.J., home as the second plane, United Flight 175, slammed into the upper stories of the south tower, where she knew that her husband, Harry, was at work. It looked to her like it had struck exactly where he was.

"It was absolutely horrible." She tried to reassure herself that her husband had told her several minutes before that he was heading down the stairwell.

In fact, Harry was still on the 67th floor, trying to get stragglers away from the windows, where they had been watching the destruction of the north tower.

"There was a huge jolt, then the ceiling came crashing down, and there was a huge gaping hole in the inside corridor," Harry would recall later. The blast, apparently, had roared down the elevator shafts and blown out the doors.

To Handler, it felt like a bomb had exploded. The plane had struck around the 90th floor, but Handler had no idea of what had happened as he moved to the stairwell.

Several flights down, he met a woman who weighed 100 pounds more than his 140. She was an asthmatic, and the smoke was making her gasp. She wanted to stop until a medic could treat her.

"No, we have to get out of the building," Handler said. He linked his arm in hers, and for the next half-hour "I was just dragging her" as they made their way slowly down the stairs. Many times, the woman begged him to stop so she could be treated for her asthma. Handler insisted she keep going.

SMOKE FILLS STAIRWELL
Firefighters, on way up, were 'going to their deaths'

In the north tower, Fred Segro and the pregnant secretary were in a stairwell when they heard a crash. Within a minute, the stairwell filled with smoke. The crash had been the United flight hitting the south tower, but Segro couldn't understand what had happened. He knew only that it wasn't good.

As they descended to the lower levels, they were slowed by firefighters, some lugging hoses, who were making their way up.

"That's the worst part, when I think about it," Segro said. "I know now they were going to their deaths.''

It took perhaps a half-hour for Segro and the secretary to reach the mall area on the ground level. It was covered with two inches of water from fire hoses and the building's sprinkler system.

Hidden in the water were shards of glass. Julie was barefoot, her high-heel shoes back on the 77th floor. Segro took off his shoes, slipped them on her feet, and they made their way to an emergency medical station.

Segro thought of a "war scene" as he beheld the number of injured. Since Julie could walk, the medics suggested that Segro get her to a nearby hospital.

As they set out, they found a pair of women's shoes on the sidewalk, perhaps left there by someone who wanted to run faster. Fred put the shoes on Julie's feet and slipped his own back on.

In the south tower, Harry Handler and the asthmatic had come to a virtual halt as stairwell traffic below the 30th floor stalled, in part because here, too, firefighters were trying to make their way up.

Handler received a message on his digital pager from a colleague in San Francisco. As they waited for the stairway to clear, Handler typed back a request that the man call his wife and tell her he was all right.

Finally, they reached the bottom. Security people led them through a below-ground concourse. They emerged on Church Street, where they found a group of medics set up.

"It was pretty horrific -- people with chunks out of their bodies," Handler said.

Handler left the woman there so she could be treated for her asthma. He headed north, to a location that Morgan Stanley had arranged long ago as a backup in the event of an emergency.

Handler's escape was well underway about 9:25 a.m. when Barbara Olson used her cellphone to call her husband, Solicitor General Theodore Olson, to tell him that her plane, American Flight 77, was being hijacked.

Olson immediately called the Justice Department command center.

PRESIDENT IS TOLD
His flight from Sarasota doesn't head for Washington

In Sarasota, Fla., President Bush had been reading to a class at Emma E. Booker Elementary School when his chief of staff whispered in his ear about the first plane assault.

To the assembled reporters and TV cameras, Bush made a brief statement, vowing to "hunt down the folks who committed this act." He said he was returning to Washington immediately.

At 9:37 a.m., over Cleveland, United Flight 93 reached a cruising altitude of 35,000 feet. Suddenly the plane turned back to the east.

Near Washington, air traffic controllers spotted a radar blip moving toward the capital. It had no transponder radioing its identity, but it was American 77, with Olson aboard. The Pentagon was notified, and over the next few minutes, horrified controllers watched as the plane stayed on a heading that carried it on a path toward the White House.

Then at 9:45 a.m., American 77 veered off that path. Moments later, going full speed, it plowed into the west side of the Pentagon, ramming through four of the five rings of the massive structure, where 20,000 people work.

Mike Cahill, 35, a paramedic for the Alexandria, Va., fire department, was driving along the George Washington Parkway near the Pentagon, listening to radio reports about the World Trade Center attack, when he saw "a huge column of smoke" rising above the trees in front of him.

Cahill stepped on the gas of his 1995 Subaru Impressa and arrived at the scene a few minutes later.

He pulled his first-aid bag out of the trunk, hopped over a barrier and rushed toward the flames. The injured were streaming out of the building. "Everyone that was coming towards me had burns,'' he would recall later. "Some of these guys still literally had smoke or steam coming off of their body or skin."

They were screaming with pain, but Cahill had no pain medication.

Some of the victims' uniforms, made of synthetic materials, had melted, not burned. Cahill cut off the clothing and doused the victims with saline solution.

He asked stunned onlookers to help him get a dozen burn victims to a nearby lawn, while secondary explosions boomed from the crash scene, about 100 yards away.

Nearby, another medic, National Guard Master Sgt. James Smith, 48, a moist T-shirt wrapped around his face, waded into the still blazing area, looking for the wounded. Burn victims were everywhere. He carried some of the wounded outside and laid them in a grassy courtyard.

Then word spread that another hijacked plane was still out there -- and that it was headed toward Washington. Security officers ordered the wounded moved about 500 yards farther from the Pentagon.

In the air over Ohio and Pennsylvania, passengers aboard United Flight 93 were using cellphones to call relatives in California.

They reported that three men speaking a foreign language were in the aisle with knives and box cutters. One carried a red box that he claimed was a bomb. At least one person had been stabbed and perhaps killed.

Mark Bingham, 31, who had his own public relations firm in San Francisco, had raced to get on this flight so he could be back in his office for a morning conference call. He called his mother and told her about the hijacking. "I love you," he said.

Over the next few minutes, Thomas Burnett Jr., 38, made four calls to his wife. An executive with a medical research company, he had been booked to come back on a later flight, but rushed to get on United 93 because he missed his wife and three daughters, all under the age of 6.

Deena Burnett was serving breakfast to the girls when the first call came to their San Ramon, Calif., home. It was 6:44 a.m. Pacific time, 9:44 a.m. in the east. Her husband said one passenger had already been killed. He and two others were "going to do something."

Jeremy Glick called his wife, Liz, who was at her parents' house with their 2-month-old daughter. Using the phone built into the seat in front of him, he held it open as Liz connected the call to a 911 dispatcher in Poughkeepsie, N.Y.

The dispatcher, Liz and her parents listened as Glick described the hijackers. He said he and several others had voted to rush the hijackers.

During her last conversation, Deena Burnett begged her husband, "Please sit down and don't draw attention to yourself."

"No," he replied. "They're going to run the plane into the ground. We're going to get up and do something."

At 9:58 a.m., a male passenger, perhaps Glick or Burnett, reached an emergency dispatcher in Pennsylvania. "We are being hijacked," said the passenger, hiding in a bathroom. He told the dispatcher that he had heard an explosion. The plane "was going down," he said.

At 10:10 a.m., United 93 crashed into a field near Shanksville, Pa. -- 80 miles southeast of Pittsburgh and 85 miles northwest of Camp David, the presidential retreat in Maryland.

'IT WAS SURREAL'
South tower's 110 stories crash shockingly to ground

About 10 minutes earlier, something happened in Manhattan that no one had ever imagined. The south tower of the World Trade Center, all 110 floors of it, came crashing down, so straight and neat that several witnesses thought it looked as if it had been planned by a demolition crew.

A mile away, on West Broadway, Bronwyn Brewer, 30, a saleswoman for a design studio, stood at a corner with many others watching the inferno engulf the top of the towers.

"You could see people jumping off the buildings. It was surreal. Everyone's face was like ghosts. People were talking on their cellphones. Some had cameras. It was shocking and horrible and unbelievable and incomprehensible."

The towers were built to withstand tremendous strain, but the Boeing 767s were each carrying more than 23,000 gallons of jet fuel, which burns at temperatures of 1,200 to 1,500 degrees -- seven times the boiling point of water. The steel in the towers, according to skyscraper expert Masoud Sanayei at Tufts University, would have begun to soften at 800 degrees.

It could have withstood the heat if the fires had been put out quickly, but there was no way for firefighters to quench that kind of blaze 1,000 feet above the street. The top floors weakened, and as the steel melted, each floor collapsed onto the one below it, sinking the tower straight into the ground.

Debbi Gibbs, the record producer, watched the collapse from her apartment a mile north of the site. The cloud blackened her windows.

On a narrow street near the towers, Fred Segro and the pregnant secretary heard the roar of the collapse and the screaming stampede of people moving away from the roar. They ducked behind a car. "Thank God, or we would have been trampled."

They waited for the choking dust and smoke to clear, then went on to the hospital, where Julie's cuts were stitched up.

Four blocks from the towers, the students at Stuyvesant High had been watching with amazement as events unfolded. Reid Monroe, 17, had been sitting in his English class, following the events on television.

One student burst into tears. Others were spreading rumors that a nearby courthouse had been bombed. "That's when I got really scared," Reid said. If a courthouse had been bombed, it meant the whole financial district could be in danger.

The collapse of the south tower made the school building tremble. From his 10th-floor classroom, Reid could see crowds running from the financial district.

Several minutes later, school officials told students to go home.

Reid had just gone outside when a new roar blasted down the street. The second tower had fallen.

Some students rushed back toward the school. Reid tried to join them, but police officers urged the students to get out. The students rushed north on the West Side Highway.

A mile away, on West Broadway, Brewer was standing in a crowd of people who were talking into their cellphones as they watched the cloud billow up from the rubble of the second collapse.

People panicked. They began running and screaming. Drivers were madly honking their horns. "People were just overwhelmed with fear," Brewer recalled. "They thought all the buildings were going to tip each other over, like a domino effect, and so they ran."

WOMAN'S HOPE FADES
Her husband was indeed on a hijacked airplane

In Abington, Mass., Christie Coombs watched the tower crashes with stunned fascination. She felt lucky. Her husband, Jeffrey, the 42-year-old Compaq manager, sometimes went to the World Trade Center on business. Instead, he was on his way to Los Angeles.

Then a TV anchor announced that the two hijacked planes were from Boston.

What flight had her husband been on? She wasn't sure. Hands trembling, the mother of three children, ages 7 to 13, called Compaq and American, trying to find out.

She was briefly hopeful when she was told that he might not have checked in.

Several times, she called his cellphone. He didn't answer.

The cascading sweep of events had stunned the White House staff.

At 9:55 a.m., Air Force One took off from Sarasota. Rep. Miller was making notes, because he knew he was on a historic flight. As the plane reached 45,000 feet over northern Florida, it suddenly changed course. It was no longer headed to Washington.

Miller was told they were headed west. At first, he wasn't sure why.

Meanwhile, the bastion of the presidency, the White House, had been deemed unsafe. Scott Stanzell, 28, a spokesman in the media office, had spent an hour huddled with colleagues around TV sets in the Eisenhower Executive Office Building, next door to the West Wing.

He kept repeating, "I can't believe this is happening."

When the news came in about the crash at the Pentagon, White House staffers realized they might be next. Some held hands. Others draped their arms around colleagues.

At 10:05 a.m. -- six minutes after the south tower collapse and five minutes before the plane crash in Pennsylvania -- alarms sounded, a steady, electronic beep, followed by a recorded male voice:

"Evacuate the White House."

Doors burst open as hundreds of staffers moved out. Secret Service agents kept telling people to move faster.

Stanzell headed across Pennsylvania Avenue, which has been closed off in front of the White House since the 1995 Oklahoma City bombing. They crossed Lafayette Park, empty of people on a beautiful, sunny September morning, past the elegant townhouses on Jackson Place. Behind them, black smoke rose into the sky from the burning Pentagon.

A few blocks away, Stanzell stopped to get a connection on his cellphone and to call his mother back home in Ames, Iowa. He wanted to tell her he was all right.

At 11:30 a.m. aboard Air Force One, President Bush summoned Miller and the other congressman on board, Adam Putnam, a Republican from Bartow in Central Florida.

Bush said he had spoken with Vice President Dick Cheney and several other advisors. He told the congressmen that intelligence learned that there had been a threat against Air Force One, and that whoever made the threat knew the code word for the plane.

"It was a serious threat," Miller recalls the president saying. "It was more than just an anonymous caller to a federal office."

"He said, 'There is a credible threat on this plane, and we're going to an undisclosed location.'"

Miller said the president assured the two congressmen that six jet fighters and another military plane were accompanying them.

"The country stands with you, Mr. President," Miller said he told the president, "and God bless you."

Putnam, a first-term Republican who says he felt a little intimidated at having a private meeting with the nation's leader, told Bush: "God bless you, Mr. President, and our prayers are with you."

SURVIVAL CELEBRATED
'People were thrilled that they had made it out'

Harry Handler of Morgan Stanley had reached his company's emergency contingency site about a mile from the twin towers. About 3,500 employees had worked in the World Trade Center complex, including some of the smaller towers, and Handler was hoping that most had made it out.

Every time a new person showed up, "we were hugging each other. People were thrilled that they had made it out."

When news came that the towers had collapsed, Handler at first couldn't believe it. Then he wondered about the asthmatic woman he had left with the medics at the base of the towers.

"They must have moved her out, don't you think?" he would ask days later.

After Handler had been at the contingency offices for about an hour, executives became nervous about a Ryder truck parked outside. Probably it had just stopped there because the bridges were closed, but no one wanted to take chances on this day.

They decided to close the office. Harry Handler and many others began walking north, toward the bridges leading to Brooklyn.

At the Pentagon, the fires and the rescues continued throughout the afternoon.

"It was unbelievably hot, like stepping into your oven," said Capt. Larry Everett, 35, a Fairfax County, Va., firefighter. The heat turned a patch on his pants' calves from tan to rust. That meant the temperatures must have been at least 800 degrees.

Capt. Ed Blunt of the Arlington County Fire Department saw six people emerge from the blazing wreckage. One was a man in his 50s wearing a military uniform. Burned skin hung from his arms. "Most of his fingers were cut off about at the palms.'' Still, he was adamant that others should be transported to the hospital before him.

Andrea Kaiser, an Arlington County firefighter, remembers most seeing clothes and shoes that must have been ripped off bodies by the force of the blast. "You saw business suits, and the shirts and the pants were still tucked in and they were burned, and you knew the bodies had to be torn apart to break away like that.''

Medic Mike Cahill called his pregnant wife, Molly. He passed his cellphone to 10 survivors, who gave Molly phone numbers for relatives so word would get out that they had made it. Molly, unable to find a piece of paper, scribbled the numbers on a vacuum cleaner bag.

Three medical sites had been set up: red for the critically injured; yellow for those with injuries that were not immediately life-threatening; and green for those with less grievous wounds.

Within two hours, hundreds of medical workers and would-be rescuers were there, Cahill recalled, but "the sad truth is, after the first hour, we spent 20 hours setting up and staffing treatment areas and we really didn't see any other patients."

It was hot as Harry Handler of Morgan Stanley and thousands of others trudged through the streets toward the Manhattan Bridge, which led to Brooklyn. In Chinatown, people lined the sidewalks, watching the financial district refugees moving out as if they were defeated soldiers retreating from a battle zone.

Thousands more were on the Brooklyn Bridge, walking right in the roadway, the bridges blocked to all cars except those of the police.

In the early afternoon, Handler arrived at his company's Brooklyn office, where he was once again met with cheers. "You're alive!"

After 6 p.m., Air Force One arrived back at Andrews Air Force Base outside Washington. Congressman Miller and the president had wandered to a Louisiana base and then to Omaha before returning.

As the plane set down, Miller looked out the window to see smoke still billowing from the Pentagon.

A SENSE OF NUMBNESS
When a busy day ended,scope of tragedy sank in

It was almost midnight when Harry Handler left the firm's Brooklyn office and walked to a nearby Marriott hotel. "It was eerie. The only things around were policemen and searchlights."

He had spent the day doing his job, trying to keep the Morgan Stanley computer system going. It was only after he was alone in a hotel room that he had time to think. His business world had crumbled, and so had many of the people in it. It was almost too much to comprehend.

Handler felt numb, paralyzed. The phone rang.

"I was shaking so hard I couldn't pick it up."

Hours earlier, in suburban Boston, Christie Coombs -- who had worried about her quick farewell kiss -- was informed by American Airlines that her husband had been aboard Flight 11. She told her three daughters.

One of them asked whether "they might find daddy" in the search of the towers' rubble.

"I said the plane blew up and there's nothing left but ashes, she said. "I don't want her to watch TV and think daddy's going to crawl out from the rubble, even if in the corner of my mind I think it would be wonderful.

"If they find anything, it would be his wedding band. That would be wonderful."